An “honest and upfront” approach from the Social Democrats not to promise undeliverable tax cuts is resonating with the electorate, the party’s deputy leader has said.

Launching the Social Democrats’ manifesto, Cian O’Callaghan insisted policy platforms put forward by other parties to invest in public services while cutting taxes were “not credible”.

Mr O’Callaghan is fronting the Social Democrats’ election campaign as party leader Holly Cairns is due to give birth this week.

Cian O’Callaghan arrives for the General Election leaders’ debate at RTE studios in Montrose (Niall Carson/PA)

He told reporters at the launch event in Dublin that he was happy with his performance in the first national TV debate of the campaign on Monday night, particularly given it was his first time in such a situation.

Mr O’Callaghan set out several policy areas that he described as the party’s “red lines” for entering a coalition government.

They are the delivery of 50,000 affordable homes in the lifespan of the next government; full implementation of the Slaintecare healthcare reforms; bolstering investment in disability services, led by a senior minister for disability; a public childcare system; and a revised Climate Action Plan.

“These are our deal breakers and making sure that these are in the next Programme for Government is absolutely key for us,” said Mr O’Callaghan.

The 50,000 affordable homes for purchase is part of a wider housing target, which also includes 25,000 affordable rental homes and 70,000 social homes in the next mandate.

“We are being very upfront, saying that you cannot have improved public services and have tax cuts at the same time,” the deputy leader added.

“It’s absolutely not credible when you look at what a lot of the other parties are promising, they’re promising huge investment in public services and very costly tax cuts at the same time.

“Now the two, you know, it’s not compatible. I think most of the electorate know that. We had a situation back in 2007 where we eroded the tax base and that caused huge difficulties in terms of the economic crash.

“So looking to erode the tax base while promising increased spending doesn’t add up. So we’re being honest and upfront with the electorate on that. And I think a lot of people do appreciate that. They know that some other parties are over-promising and will not be able to deliver on what they’re promising.”

Asked about his performance in the RTE debate, and whether he had been prominent enough in the exchanges, Mr O’Callaghan said: “I was happy with my performance. I felt I got across a lot of key points in terms of what we’re fighting on in this campaign. And look, it was obviously my first time doing a debate like that and, yeah, I was happy with my performance overall.”

Jennifer Whitmore (Brian Lawless/PA)

Mr O’Callaghan’s party colleague Jennifer Whitmore also addressed the manifesto launch event, employing Taoiseach Simon Harris’s “new energy” catchline as she aimed a broadside at Fine Gael’s record in government.

“What they’re trying to do is just cod people into think that they’re going to be different,” she said.

“We’ve had 14 years of them, and there’s no reason to believe that they’re going to change tack now.

“And really, we can have as much new energy promised as possible, but if you’re pushing new energy into old ideas and into failed policies, you’re just going to get more failed policies.”